Answer:
b) 472HZ, 408HZ
Explanation:
To find the frequencies perceived when the bus approaches and the train departs, you use the Doppler's effect formula for both cases:

fo: frequency of the source = 440Hz
vs: speed of sound = 343m/s
vo: speed of the observer = 0m/s (at rest)
v: sped of the train
f: frequency perceived when the train leaves us.
f': frequency when the train is getTing closer.
Thus, by doing f and f' the subjects of the formulas and replacing the values of v, vo, vs and fo you obtain:

hence, the frequencies for before and after tha train has past are
b) 472HZ, 408HZ
<span>If Jack is filing married-filing-separate he would report $76,000 gross income as head of household.</span>
The miracle year for Albert Einstein was the year 1905 within which he published so many renowned papers.
<h3>When was Einstein miracle year?</h3>
The miracle year for Albert Einstein was the year 1905 within which he published so many renowned papers in a short time and became very popular.
His mindset in that year was one that challenged the orthodox explanations and sought to think outside the box.
Learn more about Albert Einstein:brainly.com/question/2964376
#SPJ1
It hink that it is the 2nd one